SRC/clansb.f(3)            Library Functions Manual            SRC/clansb.f(3)

NAME
       SRC/clansb.f

SYNOPSIS
   Functions/Subroutines
       real function clansb (norm, uplo, n, k, ab, ldab, work)
           CLANSB returns the value of the 1-norm, or the Frobenius norm, or
           the infinity norm, or the element of largest absolute value of a
           symmetric band matrix.

Function/Subroutine Documentation
   real function clansb (character norm, character uplo, integer n, integer k,
       complex, dimension( ldab, * ) ab, integer ldab, real, dimension( * )
       work)
       CLANSB returns the value of the 1-norm, or the Frobenius norm, or the
       infinity norm, or the element of largest absolute value of a symmetric
       band matrix.

       Purpose:


            CLANSB  returns the value of the one norm,  or the Frobenius norm, or
            the  infinity norm,  or the element of  largest absolute value  of an
            n by n symmetric band matrix A,  with k super-diagonals.

       Returns
           CLANSB

               CLANSB = ( max(abs(A(i,j))), NORM = 'M' or 'm'
                        (
                        ( norm1(A),         NORM = '1', 'O' or 'o'
                        (
                        ( normI(A),         NORM = 'I' or 'i'
                        (
                        ( normF(A),         NORM = 'F', 'f', 'E' or 'e'

            where  norm1  denotes the  one norm of a matrix (maximum column sum),
            normI  denotes the  infinity norm  of a matrix  (maximum row sum) and
            normF  denotes the  Frobenius norm of a matrix (square root of sum of
            squares).  Note that  max(abs(A(i,j)))  is not a consistent matrix norm.

       Parameters
           NORM

                     NORM is CHARACTER*1
                     Specifies the value to be returned in CLANSB as described
                     above.

           UPLO

                     UPLO is CHARACTER*1
                     Specifies whether the upper or lower triangular part of the
                     band matrix A is supplied.
                     = 'U':  Upper triangular part is supplied
                     = 'L':  Lower triangular part is supplied

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.  When N = 0, CLANSB is
                     set to zero.

           K

                     K is INTEGER
                     The number of super-diagonals or sub-diagonals of the
                     band matrix A.  K >= 0.

           AB

                     AB is COMPLEX array, dimension (LDAB,N)
                     The upper or lower triangle of the symmetric band matrix A,
                     stored in the first K+1 rows of AB.  The j-th column of A is
                     stored in the j-th column of the array AB as follows:
                     if UPLO = 'U', AB(k+1+i-j,j) = A(i,j) for max(1,j-k)<=i<=j;
                     if UPLO = 'L', AB(1+i-j,j)   = A(i,j) for j<=i<=min(n,j+k).

           LDAB

                     LDAB is INTEGER
                     The leading dimension of the array AB.  LDAB >= K+1.

           WORK

                     WORK is REAL array, dimension (MAX(1,LWORK)),
                     where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise,
                     WORK is not referenced.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 128 of file clansb.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/clansb.f(3)